The number 61831
61831 is a composite number with 12 divisors. Its prime factorisation is 7 × × 73. Divisors (12): 1, 7, 11, 73, 77, 121, 511, 803, 847, 5621, 8833, 61831.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
61831 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
61831 is composite. Its prime factorisation is
- 3
The divisors add up to 78736; without 61831 itself that is 16905, so 61831 is deficient (16905 is less than 61831). Euler's totient φ(61831) = 47520 numbers up to 61831 share no factor with it.
- 4
The digits of 61831 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 192 steps to reach 1.
LaTeX source of the formulas on this page
\[ 61831 = 7 \times 11^{2} \times 73 \]61831 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 78736 |
| Euler totient φ(n) | 47520 |
| Square | 3823072561 |
| Cube | 236384399519191 |
| Square root | 248.658400 (= 11√511) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 192 |
| Scientific notation | 6.1831 × |
61831 in other forms
| Form | Value |
|---|---|
| In words | sixty-one thousand eight hundred and thirty-one |
| Binary (base 2) | 1111000110000111 |
| Octal (base 8) | 170607 |
| Hexadecimal (base 16) | F187 |
| Base 3 | 10010211001 |
| As time | 61831 seconds = 17 h 10 min 31 s |
Is 61831 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (61831 ÷ 7 = 8833) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (61831 ÷ 11 = 5621) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 61831 a prime number?
No. 61831 = 7 × × 73, so it is divisible by 7.
What are the factors of 61831?
1, 7, 11, 73, 77, 121, 511, 803, 847, 5621, 8833, 61831.
What is 61831 in binary?
1111000110000111 (hexadecimal F187, octal 170607).
What is the square root of 61831?
About 248.6584, exactly 11√511.
Is 61831 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 61831?
It is a composite number with 12 divisors.